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Shot of our house, taken while I was playing around to test things. It has the classic IR
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(800x600, 124.7KB)		 How to make a filter. I used 120 film because it's bigger so there's more room for cutting it out -- that would be big enough to make a 49/55mm filter for an SLR, even. I used a step-up ring because they're cheaper than even the cheapest UV filter, and as I'd just have been taking the glass out there's no need to pay for bits that I wouldn't use. The other advantage of a step-up ring is that it makes it easier to ensure that no visible light gets through, because the size of the bits of film is much larger than the size of the hole that the lens needs. A third advantage is that the step-up ring is threaded to take a 37mm (or whatever) second thing, so I just tucked the circles of film into the screw threads and they stay in place nicely, no glue needed and I can take them out if required.
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(640x516, 44.3KB)		 Back view of the filter -- notice that there's no way extra visible light could get through.
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(640x480, 38.8KB)		 Trees with the glow that they get -- this taken an hour or two before sunset, so the visible light wasn't too intense.
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I couldn't resist the urge to see how sensitive it is to generated, rather than reflected, infra-red. Answer: well, if you take a photo of a cooker ring it'll show up, but anything much cooler than that seemed to be pushing my luck.
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(800x479, 32.7KB)		 I assembled some shots into a larger panorama -- I like the contrast between foreground and background trees here.
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One nice 'hidden' feature of the Coolpix 4500 (and earlier ones) is that the sensor is still sensitive down in the infrared range. The problem, of course, is how to cut out visible light to stop it drowning the IR out -- answer: a step-up filter, a couple of thicknesses of developed, but unexposed, slide film, and voila. The slide film cuts out visible light (near enough) but lets IR through (so it doesn't melt when used in a slide projector next to a very hot bulb). See here for more info and transmission curves.
Most of these taken with exposure times of 4 to 8 seconds -- while the sensor will pick up IR light, it only just does so..
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